imported patch BitSetTools-prelim.patch

prism/src/common/BitSetTools.java

@@ -0,0 +1,87 @@
+package common;
+
+import java.util.BitSet;
+import java.util.Iterator;
+
+public class BitSetTools
+{
+	public static boolean areNonEmpty(final Iterable<BitSet> sets)
+	{
+		for (BitSet set : sets) {
+			if (set.isEmpty()) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	public static BitSet complement(final int toIndex, final BitSet indices)
+	{
+		final BitSet complement = (BitSet) indices.clone();
+		complement.flip(0, toIndex);
+		return complement;
+	}
+
+	public static BitSet minus(final BitSet set, final BitSet... sets)
+	{
+		final BitSet difference = (BitSet) set.clone();
+		for (BitSet each : sets) {
+			difference.andNot(each);
+		}
+		return difference;
+	}
+
+	public static BitSet union(final BitSet... sets)
+	{
+		BitSet union = new BitSet();
+		for (BitSet set : sets) {
+			union.or(set);
+		}
+		return union;
+	}
+
+	public static BitSet union(final Iterable<BitSet> sets)
+	{
+		return union(sets.iterator());
+	}
+
+	public static BitSet union(final Iterator<BitSet> sets)
+	{
+		BitSet union = new BitSet();
+		while (sets.hasNext()) {
+			union.or(sets.next());
+		}
+		return union;
+	}
+
+	public static BitSet intersect(BitSet set, BitSet... sets)
+	{
+		BitSet intersection = (BitSet) set.clone();
+		for (BitSet each : sets) {
+			intersection.and(each);
+		}
+		return intersection;
+	}
+
+	public static BitSet intersect(Iterable<BitSet> sets)
+	{
+		return intersect(sets.iterator());
+	}
+
+	public static BitSet intersect(Iterator<BitSet> sets)
+	{
+		if (! sets.hasNext()) {
+			throw new IllegalArgumentException("Expected at least one set.");
+		}
+		BitSet intersection = sets.next();
+		while (sets.hasNext()) {
+			intersection.and(sets.next());
+		}
+		return intersection;
+	}
+
+	public static boolean isSubset(BitSet subset, BitSet superset)
+	{
+		return minus(subset, superset).isEmpty();
+	}
+}